The mobile IPv6 (Mobile Internet Protocol version 6) described in the following Non-Patent Document 1, i.e., the MIPv6, allows a mobile node (MN) to receive packet addressed to its own home address even in a case in which it is remote from its own home network. On the other hand, laptops or other portable electronic peripherals having a plurality of network interfaces have come into widespread use. This enables an MN to handle a plurality of care-of addresses (CoAs) bound to a single home address.
In such a heterogeneous environment, for example, there is a possibility that an MN desires to spread its own input flow regarding a plurality of network interfaces, if available. Alternatively, due to an operation related to this technique, for example, there is a possibility that the MN does not desire to receive traffic in a predetermined class.
Currently, a working group (Monami6: Mobile Nodes and Multiple Interfaces in IPv6), which makes a discussion about mobile nodes and multiple interfaces in the IPV6, is making a discussion about a flow filtering mechanism. The employment of this flow filtering mechanism enables a mobile node to specify a method of re-directing the flow to its own home agent (HA). At present, the mobile node which is an object of the discussion in the Monami6 is a mobile host but almost no discussion is made with respect to a mobile router.
An object of the flow filtering mechanism is to filter different traffics to different bi-directional tunnels between the home agent and the MN. For example, the flow filtering in the Monami6 is conducted on the basis of the address of a correspondent node (CN), source and destination port numbers, IPv6 flow labels or the like.
At present, the working group contains three internet drafts (following Non-Patent Documents 2 to 4) which provide solutions regarding the flow filtering.
The internet draft “Flow movement in Mobile IPv6” in the Non-Patent Document 2 tries to introduce a new extension of the MIPv6 which allows a host to direct a reception side flow individually to an arbitrary desired interface. This extension of the MIPv6 allows a host in a multi-home state to take full advantage of various access technologies, such as establishing a connection with traffic according to a user or an internal policy specified by an application for determining the direction of the traffic.
In addition, the internet draft “Home Agent Filtering for Mobile IPv6” in the Non-Patent Document 3 tries to introduce a new filtering option regarding a binding update (BU) message. This new filtering option allows an MN to make a request to its own home agent for adding a filter to the current flow or a future potential flow. For example, the filter indicates two types of operations by the home agent. That is, for example, the filter indicates an operation in which the home agent is required to discard a packet which does not match with the filter or indicates an operation in which the home agent is required to redirect a packet, which matches with the filter, to a care-of address (CoA) associated with this filter.
Still additionally, the internet draft “Filters for Mobile IPv6 Bindings (NOMADv6)” in the Non-Patent Document 4 or the following Patent Document 1 tries to introduce a series of different filter modules usable individually or in a state combined with each other for the establishment of complex filters. Such filters are to be relayed to a binding agent during the binding update and inserted as a mobility option into signaling. In this connection, a binding agent which can maintain a filter is referred to as a filtering agent. All the filters contained in a binding update are associated with a connection point (CoA) indicated in the binding update. Thus, the filtering agent can grasp the relationship between one flow and a specified binding.
In conjunction with the flow filtering technology for a multi-interface node (node having a plurality of interfaces) in the Monami6 working group, there is the following Non-Patent Document 6 which collects the techniques disclosed in the Non-Patent Documents 2 to 4.
According to the technique disclosed in this Non-Patent Document 6, a further extension of the idea of the flow filtering takes place and a mobile router having a plurality of interfaces is made to associate one or a plurality of flows with a care-of address (CoA). Incidentally, in the Non-Patent Document 6, a flow identifier is used for the identification of binding between a flow and a care-of address.
This extension enables an MR to associate a prefix allocated to the MN itself with one of its own CoAs and register the binding related to this association in the home agent. In consequence, the home agent can transfer the flow of a destination address agreeing with this prefix to the CoA (CoA associated with this prefix) of the MR.
Yet additionally, for use, it is also possible to combine a mechanism disclosed in the following Non-Patent Document 7 with the technique disclosed in the Non-Patent Document 6. In the Non-Patent Document 7, a unique BID (Binding Identification: binding identification information) associated with a binding update message is used for the binding among a plurality of CoAs. The combination between the techniques disclosed in the Non-Patent Document 6 and the Non-Patent Document 7 enables the binding among a plurality of CoAs to be aggregated in a more effective manner.
For example, in a case in which several flow identifiers are associated with one CoA identified by a unique BID, a mobile node can change the CoA, where the bindings of these flows take place, by only changing the CoA associated with the BID.
Moreover, the combination between the techniques disclosed in the Non-Patent Document 6 and the Non-Patent Document 7 enables easily realizing an additional function such as n-cast.
In a case in which an MN tries to carry out the n-cast of traffic flow in NEMO, it is necessary that the MN is able to indicate, to an MR, a method of transferring a flow to the MN.
Still moreover, the following Patent Document 2 proposes a method of managing a communication resource for a predetermined mobile station on the basis of a type of a communication traffic associated with this mobile station. A network specifies one or more flow type profiles. Each profile contains one or more parameter values set with respect to an estimated characteristic of a packet flow represented by the profile. In addition, each flow type profile contains defined packet matching filter and an activity timer expiration period value. In an operation thereof, the network is made to maintain an effective flow set for each mobile station on the basis of one of the flow type profiles matching with a packet data traffic regarding the mobile station. Still additionally, the network makes a judgment as to whether or not the data packet to the predetermined mobile station matches with one of the defined flow type profiles.
Yet moreover, the following Patent Document 3 discloses a method whereby an MN having a plurality of network interfaces can carry out a handover management a data flow for each flow. A plurality of home addresses for the MN are registered in the HA and these addresses are dynamically allocated to different data flows between the MN and a correspondent node (CN).
The technique disclosed in the following Patent Document 4 enables a mobile terminal connectable to a plurality of heterogeneous networks to set up and maintain virtual connections through a plurality of networks to either the same or multiple destinations. This enables the improvement of reliability of communications and the realization of efficient communications.
In addition, this Patent Document 4 also discloses a case in which a multi-access terminal has a function to duplicate traffic for further enhancement of the reliability. This arrangement is useful in a case in which a link supporting flows undergoes handover, and the traffic duplication can minimize the occurrence of packet loss or delay and the interruption of services.
The technique disclosed in the following Patent Document 5 enables an access terminal to instruct a router on a method of transferring a packet in a forward direction (downlink direction) or a method of processing (and a method of delivering) a packet in a reverse direction (uplink direction) According to the technique disclosed in the following Patent Document 5, an instruction (determination and update are made by the access terminal) related to a packet flow of the access terminal is made from the access terminal to the router, and an efficient filtering on the packet is conducted in the router. Moreover, the technique disclosed in the following Patent Document 5 also realizes the bi-cast of a data stream to a desired destination owing to the efficient filtering of the packet.
The technique disclosed in the following Patent Document 6 enables a mobile node to pass information related to an access router that the mobile node is associated to on to its home agent or other corresponding nodes. Utilizing this information, a home agent or corresponding nodes are able to send packets directly to a mobile node without incurring the overheads from route triangulation. Moreover, it is possible for the home agent or corresponding nodes to verify that a packet arriving through a tunnel with one outer source address of access routers is from an authentic source. This is due to the fact that a recipient can verify the reliability of a forwarding router, thus allowing a mobile router to forward an outer packet directly to a specified destination.
[Patent Document 1] A. Lundstorm and H. Basilier, “Applications based radio resource management in a wireless communication network”, U.S. Patent Application Publication 2003/0235171A1, December 2003.
[Patent Document 2] Yamada, Mariko, Takeda, Yukiko, Morishige, Takehiro and Takahashi, Katsunori, “Mobile node, server, and communication system”, U.S. Patent Application Publication 2006/0018273A1, January 2006.
[Patent Document 3] Gallego Catalina, Miguel and Janneteau, Christophe, “Data flow handover in communication using mobile internet protocol”, EP Patent Application Publication 02293180, December, 2002.
[Patent Document 4] P. White and N. Girard, “Multi-access terminal with capability for simultaneous connectivity to multiple communication channels”, U.S. Patent Application Publication 2006/0193295A1, Nov. 18, 2005.
[Patent Document 5] P. McCann, R. Ejzak, M. Dolan and F. Alfano, “Method for reducing service interruptions during a hand off in a wireless system”, U.S. Patent Application Publication 2005/0232198A1, Apr. 4, 2004.
[Patent Document 6] C. W. Ng, P. Y. Tan and T. Ue, “Method and device for roaming-connection in global network”, PCT Patent Application Publication WO/2004/036841, Apr. 29, 2004.
[Non-Patent Document 1] D. Johnson, C. Perkins and J. Arkko, “Mobility Support in IPv6”, Internet Engineering Task Force Request For Comments 3775, June 2004.
[Non-Patent Document 2] H. Soliman, K. ElMalki, and C. Castelluccia, “Flow movement in Mobile IPv6”, Internet Draft, June 2003.
[Non-Patent Document 3] N. Montavont and T. Noel, “Home Agent Filtering for Mobile IPv6”, Internet Draft, July 2003.
[Non-Patent Document 4] K. Kuladinithi, N. A. Fikouras, C. Goerg, Koltsidas Georgios and Fotini-Niovi Pavlidou, “Filters for Mobile IPv6 Bindings (NOMADv6)”, Internet Draft, October 2005.
[Non-Patent Document 5] V. Devarapalli, R. Wakikawa, A. Petrescu and P. Thubert, “Network Mobility (NEMO) Basic Support Protocol”, Internet Engineering Task Force Request For Comments 3963, January 2005.
[Non-Patent Document 6] H. Soliman, N. Montavont, N. Fikouras and K. Kuladinithi, “Flow Bindings in Mobile IPv6”, Internet Engineering Task Force Internet Draft, Oct. 23, 2006.
[Non-Patent Document 7] R. Wakikawa, T. Ernst and K. Nagami, “Multiple Care-of Addresses Registration”, Internet Engineering Task Force Internet Draft, October 2006.
However, in a case in which a flow filtering mechanism described in the Monami6 is applied to the network mobility (NEMO) in the Non-patent Document 5, the tunnel terminates at a mobile router (MR), while the traffic terminates at an MN. Since the MR cannot grasp the traffic requirements on a flow to the MN for achieving intelligent flow filtering, if the MR has an egress access, a problem arises in a flow filtering mechanism. In addition, it is impossible that the MN grasps a characteristic (egress characteristic) of an access network for the implementation of the intelligent flow filtering on the basis of various mobile network prefixes (MNPs) notified from the MR.
That is, in a case in which the concept of the NEMO is applied to the Monami6, a bi-directional tunnel through which traffic up to the MN within the mobile network passes, terminates at the MR. For this reason, for example, if there are a plurality of egress routes in the mobile network with which the MN is in connection (for example, in a case in which one MR has a plurality of egress interfaces, when a plurality of routers each having an egress route exist within the mobile network, or in other cases), it is impossible that the MN carries out the flow filtering in a state where sufficient consideration is given to the characteristic (egress characteristic of the MR) of a network lying at a higher-order position of the MR. Accordingly, there is a problem which arises at the present stage in that difficulty is encountered in applying the concept of the NEMO completely to the Monami6.
In addition, in the case of the employment of the technique in the Patent Document 2, even if the MR executes the matching function, the mobile station cannot acquire the egress characteristic of the MR, so the above-mentioned problem regarding the NEMO still exists.
Still additionally, in the case of the technique in the Patent Document 3, although there is the description to the effect of using the standard mobile IPv6 technology so that the HA can notify a plurality of home addresses to the MN, if an MR is introduced thereinto, it is impossible to notify egress conditions of the MR to the MN through the use of the standard mobile IPv6 mechanism.
Yet additionally, with the technique in the Patent Document 4, there exists a problem in that, when one mobile terminal (first mobile terminal) is positioned under a different mobile terminal (second mobile terminal) so as to establish an nested state, the determination on the duplication of the traffic is made by the second mobile terminal (host mobile terminal). Accordingly, this leaves very little control scope to the original data sender/receiver (i.e., the first mobile terminal), which is naturally made to carry out the determination control on the duplication of the traffic flow, when it is placed into a nested state under a different mobile terminal.
Moreover, in the case of the technique in the Patent Document 5, there exists a problem in that, when one access terminal (first access terminal) is positioned under a different access terminal (second access terminal) so as to establish an nested state, the first access terminal cannot grasp the fact that the second access terminal has a plurality of links when setting a special filter.
Furthermore, in the case of the technique in the Patent Document 6, there exists a problem in that, a home agent or correspondent node is unable to filter the traffic flows of the mobile node via a mobile router with multiple egress routes (e.g. care-of addresses). The reasoning being that the mobile node does not know the care-of addresses of the mobile router, thereby the mobile node is unable to set filters at the home agent or correspondent node specifying which route to use for the various traffic flow of the mobile node. Similarly, the mobile router has no knowledge on how the mobile node wants the traffic flow to be routed.